OK, originally my problem is the backup and restore.
Sometimes my users delete an e-mail or a complete subfolder. And my user want restore the deleted item(s) (in this sample case the user deleted all items from the trash also).
After 2-3 days the user come to me and ask me "Can you restore the deleted subfolder?" I can't answer: "No".
This is the situation I hope You understand I am.

The Zimbra's automatic incremental backup is not good in this case. I can't restore the whole user's mailbox in an earlier date because the new e-mails will missing after the deleting time.

I currently use a "single" linux-based e-mail server with Postfix and Courier-IMAP. The user's e-mails stored in Maildir format, each user has a seperated directory and in this directory are subdirectories (Inbox, Sent, Drafts,...).
I create daily full backup from this Maildir folders each user has a daily .tgz backup file. I have backups for the last two weeks.
If my user delete an e-mail I can restore an e-mail from the backup and I can copy to the user's right subfolder.

But the Zimbra store I can't do this.
In the Zimbra store and in the daily backups not shown the user, subfolders...
This is my problem.

Otherwise how can I restore a deleted user's subfolder which is contains many sorted e-mails after 3 days in Zimbra? I think the store in Maildir format is a solution for this problem.

OK, originally my problem is the backup and restore.
Sometimes my users delete an e-mail or a complete subfolder. And my user want restore the deleted item(s) (in this sample case the user deleted all items from the trash also).
After 2-3 days the user come to me and ask me "Can you restore the deleted subfolder?" I can't answer: "No".
This is the situation I hope You understand I am.

If the user deletes an email (or folder) it's stored in the Trash folder for 30 days (or whatever the retention period is), if the user then deletes the email or folder from the Trash folder then it's gone (i.e. it's removed completely form the HD - you or the user then have a problem) - access to the directory structure will do you no good at this stage. There is a recently introduced feature named Dumpster that should help, search the Admin Guide for details on it's usage. I don't know why people delete stuff from the Trash folder but I guess you should educate them that they will completely lose the mail by doing that.

If the user deletes an email (or folder) it's stored in the Trash folder for 30 days (or whatever the retention period is), if the user then deletes the email or folder from the Trash folder then it's gone (i.e. it's removed completely form the HD - you or the user then have a problem) - access to the directory structure will do you no good at this stage. There is a recently introduced feature named Dumpster that should help, search the Admin Guide for details on it's usage. I don't know why people delete stuff from the Trash folder but I guess you should educate them that they will completely lose the mail by doing that.

Thanks. I know this function.
The mails in the Trash is calculated in the quota? - I think this will is a cause for the "deleting from trash".

I think the deleting has two "options":
1) Chance. The user did'n want delete the e-mail. In this case the deleted e-mail is in the Trash. That is ok, can we recovering from Trash.

2) Intentional delete. The user want delete the e-mail(s) or subfolder (e.g. quota limit, cleansing,...) and in this case the user will remove the deleted items from the Trash also. After (few days) this the user reconsider the delete operation. This is the problem.
The user deleted the data from the Trash also.
The user become and sent a few e-mails after the deleting.
The user want restore the deleted item(s). And the Zimbra's recovery is not option because this will restore the whole mailbox and the new e-mails (since deleting) will be lost.
I can't say for my boss in this case: "This is the situation and go away!"
He ask: "No backup? Why not backup?!"
I can't say: "We have backup....but...I can't recover from your deleted e-mails what you deleted 2 days ago because you will lose all e-mails that you become in the last 2 days..."

This is my problem and I search a solution for this.
The good solution would a "backup explorer" on the Zimbra admin page. The administrators can browse the backup and will select and restore one or more items to the real mailbox - without complete mailbox overwrite with an 2 days old state...

Giving your users an unrealistic quota doesn't help this situation, HD storage is relatively inexpensive and by far the best option for preserving your sanity and the users email. You really should educate your users about the Dumpster function (are you saying it doesn't work or the user can't use that feature?) and the fact that if they delete the email from the Trash folder then it gets totally removed from the system.

Originally Posted by _Mono_

The administrators can browse the backup and will select and restore one or more items to the real mailbox - without complete mailbox overwrite with an 2 days old state.

You don't have to overwrite the current mailbox when you do a restore, you restore it to a new account and the copy the required mail to the original account.